1. NuMI NBI2003 November 7-11, 2003 NuMI Target Jim Hylen / FNAL Page 1 NuMI Target Status, Testing, Support Module At NBI’02: Beam test results of Medium Energy style target (graphite fin clamped by aluminum cooling plates) Design shown of Low Energy target (graphite soldered to Stainless water pipes) At NBI’03: Low Energy target construction complete Vibration testing of target in progress Design complete of target carrier (assembly begun) which allows remotely changing neutrino beam energy Outlook: Install target in target hall – June 2004 Measure hadron production using (spare) target in MIPP/E907 experiment - Fall 2004 Commission NuMI with beam – December 2004

2. NuMI NBI2003 November 7-11, 2003 NuMI Target Jim Hylen / FNAL Page 2 NuMI target collaboration IHEP Protvino design team V.Garkusha, V.Zarucheisky F.Novoskoltsev, S.Filippov, A.Ryabov, P.Galkin, V.Gres, V.Gurov, V.Lapygin, A.Shalunov, A.Abramov, N.Galyaev, A.Kharlamov, E.Lomakin, V.Zapolsky FNAL design team J.Hylen, K.Anderson FNAL beam test J.Morgan, J.Hylen, H.Le, A. Kulik, P. Lucas, G. Koizumi ANL vibration test R.Wagner Energy deposition calculations done with MARS Target construction done at IHEP

3. NuMI NBI2003 November 7-11, 2003 NuMI Target Jim Hylen / FNAL Page 3 NuMI target types (Low Energy refers to neutrino spectrum, not beam power) Low Energy Target must fit in horn this is what we have built Medium Energy Target easier, more robust Graphite (POCO ZXF-5Q) is target material

4. NuMI NBI2003 November 7-11, 2003 NuMI Target Jim Hylen / FNAL Page 4 Different spectra obtained by changing target and moving 2 nd horn L.E. gives MINOS best match to current SuperK  m 2

5. NuMI NBI2003 November 7-11, 2003 NuMI Target Jim Hylen / FNAL Page 5 Reasonable High Energy beam can be produced by just moving LE target “Semi-beams” Full Beams Just moving LE target New target, move horn 2

6. NuMI NBI2003 November 7-11, 2003 NuMI Target Jim Hylen / FNAL Page 6  spectra moving off-axis Future off-axis experiment in Minnesota? Off-axis experiment probably prefers M.E. configuration 2 GeV beam off-axis L.E. M.E.

7. NuMI NBI2003 November 7-11, 2003 NuMI Target Jim Hylen / FNAL Page 7 Low Energy Target Construction Graphite Fin Core 2 int. len. Water cooling tube also provides mechanical support Aluminum vacuum tube

8. NuMI NBI2003 November 7-11, 2003 NuMI Target Jim Hylen / FNAL Page 8 Target – Internal Monitoring Narrow – location checked by scanning beam across edge. Sense by: (i) charge (delta-rays) knocked out (wire connected to target) (called Budal) (ii) scattered beam into cross hairs ionization chamber (BLM) Casing of target fin electrically insulated from base. Wire strung from case to top of module. When moving, can sense if case touches horn by short to “ground”.

9. NuMI NBI2003 November 7-11, 2003 NuMI Target Jim Hylen / FNAL Page 9 Will use Helium instead of vacuum for high beam power running Aluminum vacuum tube is insulated from water cooling to allow Budal monitor to work. At design beam power, conduction from tube through helium to water pipe is important. (downstream end still reaches 190 deg C). Can still use vacuum for low power beam alignment scans

10. NuMI NBI2003 November 7-11, 2003 NuMI Target Jim Hylen / FNAL Page 10 NuMI target vibration testing Target tip vibration induced by: Pulsing horn < 0.01 mm (Target does not touch horn 2.5 mm clearance) Air flow similar to target hall ~ 0.06 mm Air flow with target out of horn ~ 0.5 mm (need to redo with outer tube in place) Water flow (not measured yet) Target in L.E. location in horn

11. NuMI NBI2003 November 7-11, 2003 NuMI Target Jim Hylen / FNAL Page 11 Target Temperature (Calculation) - lots of headroom NuMI beam design parameters: 0.4 MW beam power 120 GeV/c proton beam 4x10 13 protons per 8.6  sec beam spill 1.87 sec repetition rate 1 mm RMS circular beam spot size

12. NuMI NBI2003 November 7-11, 2003 NuMI Target Jim Hylen / FNAL Page 12 Target dynamic stress calculation Safety factor of 3.8 at fin center Safety factor of 2.2 at curved edge of fin Note fin is in 2 cm segments to prevent stress buildup

13. NuMI NBI2003 November 7-11, 2003 NuMI Target Jim Hylen / FNAL Page 13 Radiation Damage is still the big uncertainty Most radiation damage info is from reactor neutrons In this example, graphite self- destructs at ~ 2x10 20 n/mm 2 Highest radiation density in NuMI target is proton spot near entrance ~ 0.5x10 20 p/mm 2 / year NuMI target test accumulated 0.023x10 20 p/mm 2 with no visible damage Target longevity uncertain – will gain experience in 2005 Radiation Damage and Life-time Evaluation of RBMK Graphite Stack, XA9642904, P.A.Platonov, O.K.Chugunov, V.N.Manevsky, V.I.Karpukhin, Russian Research Center Kurchatov Institute

14. NuMI NBI2003 November 7-11, 2003 NuMI Target Jim Hylen / FNAL Page 14 Baffle Protects beamline elements (e.g. target water lines) from mis-steered proton beam that could do damage in a single pulse Graphite encapsulated in aluminum tube 150 cm long, 6 cm diamter 11 mm diameter hole for beam Air-cooling boosted by pin radiators Scraping of a few percent of beam here would affect neutrino spectrum Detect scraping by temperature rise

15. NuMI NBI2003 November 7-11, 2003 NuMI Target Jim Hylen / FNAL Page 15 Target station in pictures (10% of ) Shielding Blocks 1 of 3 Support modules 1 of 2 focusing horns Target with motion system

16. NuMI NBI2003 November 7-11, 2003 NuMI Target Jim Hylen / FNAL Page 16 Target and Horn hang from support/shielding modules Water tank Baffle Target Target/Baffle Module Horn 1 Module Horn 1 Carrier

17. NuMI NBI2003 November 7-11, 2003 NuMI Target Jim Hylen / FNAL Page 17 Target / Baffle can be remotely moved 2.5 m along beam direction, 20 cm vertically, +/- 8mm horzontally Drive motors Baffle Target Shielding / Support Module T/B Carrier Vertical motion gets target out of way for beam scan of horn cross hairs

18. NuMI NBI2003 November 7-11, 2003 NuMI Target Jim Hylen / FNAL Page 18 Target/Baffle Carrier Target Water lines compress like spring Baffle Dirt on screw drive test – no problem Support shafts move whole carrier for transverse motion but motion along beam uses ball screw below module to push/pull cradle Rollers

19. NuMI NBI2003 November 7-11, 2003 NuMI Target Jim Hylen / FNAL Page 19 NuMI Target Summary At NBI’02: Beam test results of Medium Energy style target (graphite fin clamped by aluminum cooling plates) Design shown of Low Energy target (graphite soldered to Stainless water pipes) At NBI’03: Low Energy target construction complete Vibration testing of target in progress Design complete of target carrier (assembly begun) which allows remotely changing neutrino beam energy Outlook: Install target in target hall – June 2004 Measure hadron production using (spare) target in MIPP/E907 experiment - Fall 2004 Commission NuMI with beam – December 2004